/Engine/Source/Runtime/Engine/Classes/Kismet/KismetMathLibrary.h
Breaks a direction vector apart into Azimuth (Yaw) and Elevation (Pitch) rotation values given in degrees. (non-clamped) Relative to the provided reference frame (an Actor's WorldTransform for example)
static void GetAzimuthAndElevation ( FVector InDirection, const FTransform & ReferenceFrame, float & Azimuth, float & Elevation )